Heat Exchange Between Ocean and Atmosphere in the 

 Eastern North Pacific for 1961-71 



N. E. CLARK, L. HBER, R. M. l.AURS. J. A. RENNER, and J. F. T. SAUR' 



ABSTRACT 



Summaries of large-scale heat exchange between ocean and atmosphere in the eastern North Pacific 

 Ocean are presented for the period 1961 through 1971. The summaries are based on computations made 

 from synoptic marine radio weather reports and include I) monthly values of total heat exchange and 

 departures from a long-term mean; 2) long-term monthly mean values of the total heat exchange, incom- 

 ing solar radiation, effective back radiation, and evaporative and sensible heat transfer; and 3) annual 

 cycles of total heat exchange for selected areas. 



Outstanding spatial and temporal features of the heat exchange values are discussed. However, little 

 detail is given since this is a summary report, and readers can draw their own conclusions depending upon 

 the intended use of the charts. 



Comparisons are also made between the total heat exchange values and those given in two other 

 reports. Discrepancies between values given in this report and those published in the other reports are 

 attributed to differences in the empirical equations used to make the heat exchange computations, differ- 

 ences in data processing techniques, differences in the observed data used in the computations due to 

 difTerent methods of acquisition, and the possibility of ocean climate changes. 



INTRODUCTION 



The ocean's thermal structure is an important en- 

 vironmental variable that affects the distribution and 

 abundance of marine fish populations (Sette, 1961; 

 Uda. 1957, 1961). As part of a fisheries oceanography 

 research program directed towards fisheries predic- 

 tion, ocean temperature conditions and the air-sea 

 interaction processes which are most often responsible 

 for changes in this structure have been monitored in 

 the eastern North Pacific since 1960. These data have 

 been used to describe the interaction of ocean and 

 atmosphere (Clark, 1972; Namias, 1969, 1971) in the 

 eastern North Pacific and to identify and attempt to 

 understand those ocean features that are important de- 

 terminants of tuna distribution (Johnson, 1962; Flitt- 

 ner, 1970). They are also being used to evaluate the 

 role of changing ocean conditions on other fish popula- 

 tions. 



This report is a contribution to the MARMAP pro- 

 gram of the National Marine Fisheries Service and 

 presents summaries for use by fishery and other marine 

 scientists of the derived heat exchange between ocean 

 and atmosphere in the eastern North Pacific Ocean 

 bounded by lat. 20° and 60°N and long. 1 15°W and 180° 

 for the period 1961-71 . The summaries were computed 

 by 5° latitude-longitude quadrangles and are presented 

 on charts of 1) the monthly values of total heat ex- 

 change and differences from the long-term mean; 2) the 

 long-term monthly means of the total heat exchange, 



'Southwest Fisheries Center. National Marine Fisheries Service. 

 NOAA. 8604 La Jolla Shores Drive, La Jolla, CA 92037. 



incoming solar radiation, effective back radiation, and 

 evaporative and sensible heat transfer; and 3) the an- 

 nual cycles of total heat exchange in selected areas. 



Since air-sea interaction processes cannot, in gen- 

 eral, be measured directly except for solar radiation, 

 for which there are very limited measurements over 

 the oceans, quantitative evaluation of these processes 

 depends upon computations based on empirically de- 

 rived formulas. Because these formulas are still the 

 subject of extensive research, the heat exchange com- 

 putations should be considered only as relative indices 

 of the magnitude of the heat flux across the air-sea 

 interface. However, we believe that the computations 

 represented by the charts in this report can be used to 

 evaluate large-scale features and to show year-to-year 

 and month-to-month variations of this heat flux. 



SOURCE AND DISTRIBUTION 

 OF THE DATA 



The source of data used in preparing the charts in 

 this report is the synoptic marine radio weather report 

 made by ships at sea. Cooperating American and 

 foreign-flag vessels make, record, and transmit the 

 standard marine weather observations according to es- 

 tablished procedures set up by the World Meteorolog- 

 ical Organization (WMO). Observations taken at 

 0000, 0600, 1200, and 1800 Greenwich Mean Time 

 daily are transmitted to designated commercial and 

 government radio stations around the world. 



Between 8,000 to 10,000 synoptic marine weather 

 observations from the eastern North Pacific are pro- 

 cessed by computer each month at the National 

 Marine Fisheries Service La Jolla Laboratory, and 



